IRON (Fe) 55.84 Atomic Weight
Iron is an essential element to plants, animals, and humans. It is the fourth most abundant element, constituting 5.0% of the earth’s crust. It is the second most abundant metal element, and as the chief constituent of the earth’s core, it is the most abundant element in the overall mass of the earth. It is also relatively plentiful in the sun and other stars as well as solid extraterrestrial objects such as meteors, which are classified by Iron content. Iron is found combined with other elements in hundreds of minerals.
In humans and animals, Iron is part of the active site of hemoglobin, and carries Oxygen in the bloodstream. It constitutes about 0.004 percent of the body, of which approximately 65% of that is in the form of hemoglobin; 1.0% is used in enzyme activity that controls intracellular oxidation; the balance is stored in various organs for future manufacture of hemoglobin. Red meat, eggs, vegetables and fruit are sources of Iron for the body.
In plants, the sulfate compound is an essential source of Iron, which utilizes it in the formation of chlorophyll in plant cells. It serves as an activator for biochemical processes such as plant respiration, photosynthesis, and symbiotic nitrogen fixation. Deficiencies can be induced by high levels of Manganese or lime content in soils. Iron is taken up by plants either in the ferrous (Fe++) or (Fe+++) ions.